Don't let your employees do this!  Teach them to use the two simple words "I'm sorry!" – and mean them!  This will make a big difference in how your customers deal with your mistakes.  It's pretty simple really:

If you forget to call someone back, just say you are sorry!

If you take too long to do something, just say you are sorry!

If you totally ruin someone’s house and they have to stay in a hotel for a week while you repair it, just (really, really, really) say you are sorry

If a customer sends you an email and you don't see it for a week, jump on it immediately, and just say you are sorry.  Don't pretend you didn’t make the mistake, and don't think that because they don’t rake you over the coals it must not have meant anything to them; I assure you it did.

I’m amazed at how people forget to return my call, don't deliver something they promised, or take three times longer than their estimate, but don’t bother to say "I'm sorry!"  If delivered from the heart, these are just flat out magic words. I find they quench the fire of my frustration nearly every time.

At Conditioned Air, we encourage our people to bend over backwards to give any non-abusive, honest customer the benefit of the doubt, often accompanied by those magic words.  And then we make it right (how we do that obviously depends on the situation).  You should do the same: encourage your people to admit their mistakes to your customers and then fix them.

Ah, you say, but what about abusive, nasty, mean-spirited customers? Well, if you messed up, say you are sorry.  And if they really are abusive, stop doing business with them.  You can't control their attitude, only your own.

Of course, being sorry isn't enough in and of itself.  If you screw up constantly, you are going to have a hard time keeping customers no matter how much you apologize (I doubt it would make much difference in Ryan's breakfast example from the other day).  But if you deliver a decent product or service, a little humility and the appropriate apology will do wonders for your customer relationships.